The present invention relates to a running gear for a rail vehicle, comprising a wheel unit, a motor unit and a running gear frame unit. The running gear frame unit defines a longitudinal direction, a transverse direction and a height direction, and is supported on the wheel unit, while the motor unit is connected to the wheel unit to drive the wheel unit. The motor unit is suspended to the running gear frame unit via a connecting device. The present invention further relates to a rail vehicle comprising such a running gear.
In modern rail vehicles, in particular, modern high-speed rail vehicles, two basically different approaches may be taken to suspend the electric drive motors within the running gear. A first approach is to suspend the motor primarily to the axle of the wheel unit (such as e.g. a wheel set or a wheel pair) as it is known, for example, from US 2010/0116167 A1 (Körner). The connection to the running gear frame typically via one or more elastically connected pendulums of a torque support serving to support the drive torque of the motor. Such a solution may have the advantage that within the drive train from the motor shaft to the wheel set shaft, relative motion affecting proper tooth engagement may be largely avoided. However, this approach has the disadvantage that the mass of the motor to a large extent contributes to the so-called unsprung or non-suspended mass of the running gear, i.e. the mass of the running gear which is not suspended via at least one (primary or secondary) spring system. In particular for high-speed applications, such a high unsprung mass is undesirable in terms of the dynamic and acoustic properties of the running gear.
A different approach, as is known, for example, from JP 62016036 A (Ando et al.), substantially rigidly suspends the motor to the running gear frame. While this approach reduces the unsprung mass, it has the disadvantage that the inertia of the running gear frame unit, in particular, the inertial moment about the height axis, is increased due to the additional mass of the motor. Such a high inertial moment also has certain dynamic disadvantages in terms of the running stability of the running gear, in particular and high speeds.